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25 November 2014, Volume 2014 Issue 6 Previous Issue    Next Issue

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Quantum Schur superalgebras and finite general linear groups CHEN Xiao-Yu, WANG Jian-Pan 2014, 2014 (6):  1-8.  doi: 10.3969/j.issn.1000-5641.2014.06.001 Abstract ( 1167 )   PDF (148KB) ( 1790 )   Save This paper realizes quantum Schur superalgebras as the endomorphism algebras of certain representations of general linear groups over finite fields, generalizing the relationship between quantum Schur algebras and finite general linear groups established by Beilinson, Lusztig, and MacPherson and described in details in the monograph Finite Dimensional Algebras and Quantum Groups by Deng, Du, Parshall, and Wang. Related Articles | Metrics

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Characterization of potent rings YING Zhi-Ling, WENG Ye-Zao 2014, 2014 (6):  9-11.  doi: 10.3969/j.issn.1000-5641.2014.06.002 Abstract ( 1079 )   PDF (199KB) ( 1647 )   Save This paper proved that a ring R is potent iff Spec(R) has a clopen pi-base and its idempotents can be lifted modulo J(R). The result gives a characterization of potent rings. Related Articles | Metrics

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Biharmonic hypersurfaces with at most twodistinct principal curvatures in Esn+1 YANG Chao, LIU Jian-Cheng 2014, 2014 (6):  12-16.  doi: 10.3969/j.issn.1000-5641.2014.06.003 Abstract ( 1048 )   PDF (176KB) ( 1717 )   Save In this paper, we studied biharmonic hypersurfaces of pseudo-Euclidean space Esn+1with at most two distinct principal curvatures. Assume the shape operator is diagonalizable, we proved that such hypersurfaces are minimal. Related Articles | Metrics

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Perturbation of single-valued extension property and its application DAI Lei, CAO Xiao-Hong 2014, 2014 (6):  17-24.  doi: 10.3969/j.issn.1000-5641.2014.06.004 Abstract ( 1316 )   PDF (279KB) ( 1589 )   Save A new spectral set was defined on the basis of being consistent in Fredholm and index. By applying the new spectral set and a variant of the essential approximate point spectrum, the compact perturbation of the single-valued extension property was studied. Also, the equivalent characterization of the generalized property (ω) was proposed. Related Articles | Metrics

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Oscillation of higher order functional differential equations with positive and negative coefficients and damping term YANG Jia-Shan 2014, 2014 (6):  25-34.  doi: 10.3969/j.issn.1000-5641.2014.06.005 Abstract ( 1286 )   PDF (286KB) ( 1672 )   Save The oscillation for a class of even order nonlinear variable delay damped functional differential equation with positive and negative coefficients and nonlinear neutral term was discussed. By introducing parameter function and the generalized Riccati transformation, using H¨older inequality and some necessary analytic techniques, some new criteria for the oscillation of the equation were proposed. These criteria improve and generalize some known results. Examples were given to illustrate the main results. Related Articles | Metrics

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A new proof of the generalized Craig-Sakamoto theorem DU Cui-Zhen 2014, 2014 (6):  35-38.  doi: 10.3969/j.issn.1000-5641.2014.06.006 Abstract ( 1136 )   PDF (174KB) ( 2054 )   Save We gave a new proof of the generalized Craig-Sakamoto theorem, which asserts that two normal matrices A and B satisfy det(I − aA − bB) = det(I − aA)det(I − bB) for all complex numbers a and b if and only if AB = O. Related Articles | Metrics

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Pricing warrant bonds under a Markov-modulated jump diffusion process WANG Wei, ZHAO Qi-Jie 2014, 2014 (6):  39-48.  doi: 10.3969/j.issn.1000-5641.2014.06.007 Abstract ( 1182 )   PDF (482KB) ( 1552 )   Save By the method of measure transformation and no arbitrage pricing theory, the explicit analytical formula of warrant bonds was obtained when the risky asset followed the Markov-modulated jump diffusion process and the market interest rate was stochastic. Moreover, a numerical analysis was provided by the Monte Carlo method, and the value of warrant bonds was compared when the risky asset satisfied different financial models. Related Articles | Metrics

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Effect of nonlinear coefficient and edge weight on complex networks QIAN Ying-Feng, LI Qing-Li, LIU Hong-Ying 2014, 2014 (6):  49-56.  doi: 10.3969/j.issn.1000-5641.2014.06.008 Abstract ( 1035 )   PDF (571KB) ( 1776 )   Save In this paper, standard SIR model of rumor In this paper, standard SIR model of rumor spreading is used in the weighting complex networks. The tie strength is expressed by the function of edge weight\textit f(ω) in order to simulate the function between relationship and reliant interpersonal. In the practical scene, a node may only be contacted by some of its neighbors, so that the nonlinear rumor spread exponent α of Anurag Singh (2013) is introduced, and the rumor spreading in complex networks is discussed. The effect of \textit f(ω) and α on the rumor threshold is discussed in the paper. It is found that the mean edge weight<ωkk'together with its function\textit f(ω) and μ are both effect the steady state value of r(t), that is \textitr(∞), which means the rate of people who heard the rumor in the crowd. And the explosion time is also effected by them. In the research, a positive tumor threshold λc had not been found when the \textit f(ω) and μ are introduced. Related Articles | Metrics

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Level set evolution model with inter-region dissimilarity CHEN Wen, ZHU Min 2014, 2014 (6):  57-66.  doi: 10.3969/j.issn.1000-5641.2014.06.009 Abstract ( 1066 )   PDF (1102KB) ( 1536 )   Save Level set method has been widely used in image segmentation. Edge-based active contour model mainly drives the curve to the target boundary by gradient information, but the model based on gradient information makes the segmentation produce over-segmentation. And for the uneven gray image, the processing results are not so satisfactory.\linebreak However, the region-based active contour model controls the curves evolution through regional information, which will get the segmentation results based on the whole image. For the reasons stated above new regional component is put forward in the Level set, by utilizing the square of mean gray value difference between the background and the target area in energy function, a new improved method for image segmentation is proposed. Compared with the general active contour model, the experimental results show that the active contour model~with the regional difference information has ideal effect of segmentation,~faster evolution speed and higher efficiency. We can get more satisfactory segmentation results. Related Articles | Metrics

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Influence of vacuum annealing on the GMI effect of Co81.5Fe4.5Mo2B12 microwires ZHANG Heng-Guang, LI Xin, RUAN Jian-Zhong, CHEN De-Lu, ZHAO Zhen-Jie 2014, 2014 (6):  67-72.  doi: 10.3969/j.issn.10005641.2014.06.010 Abstract ( 1272 )   PDF (2132KB) ( 1396 )   Save Co81.5Fe4.5Mo2B12 microwires were prepared by the TaylorUlitovsky method. Influence of the vacuum annealing conditions on Giant Magnetoimpedance (GMI) effect and its symmetrical properties were studied. The results show that the GMI ratio increases firstly and then decreases with the increase of the annealing temperature. The highest GMI ratio was obtained when the temperature is 250 ℃. The symmetry of the GMI curves of the microwires may be improved after proper annealing. When the annealing temperature is 330 ℃, GMI symmetry of the microwire was deteriorated may be caused by the decrease of the magnetic anisotropy. Related Articles | Metrics

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Adaptively determining clustering number of K-means: A case study on the clustering from remotely sensed imagery YUAN Zhou-Mi-Qi, ZHOU Jian-Hua 2014, 2014 (6):  73-80.  doi: 10.3969/j.issn.10005641.2014.06.011 Abstract ( 1432 )   PDF (3169KB) ( 1586 )   Save A new algorithm, named adaptively determining the number of clusters (ADNC), has been proposed. By using ADNC, the optimal clustering number for Kmeans clustering, usually determined by human conjecture or manual try, can now be determined by computer in a self-adaptive way.ADNC typically is an iterative process including the adjustment of clustering number and the assessment of average standard deviation during the iteration. The adjustment will refer the assessment following the principle of gradient descent, namely, to get a better clustering number and to reduce the deviation in the same time. The optimal clustering number most likely locates at the point just before the deviation begins to oscillate. The clustering results will be perfectly reasonable with the clustering number decided by ADNC because the feature heterogeneity in a class will be reduced to the minimum. By the way, the concept of inappropriate clustering number, by using which the deviation may increase to the maximum, has been proposed as a try. It has been revealed by experiment that both the optimal and the inappropriate clustering numbers have practical significance to improve the clustering accuracy. Related Articles | Metrics

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Sensitivity analysis of parameters in the numerical storm surge forecast model in the East China Sea WU Hui-Ming, GAO Qing-Qing 2014, 2014 (6):  81-89.  doi: 10.3969/j.issn.10005641.2014.06.012 Abstract ( 1048 )   PDF (1938KB) ( 1824 )   Save Based on two simulated typhoons, the sensitivity analysis was carried out for the numerical storm surge forecast model in the East China Sea with northward typhoon. Using the stormsurge calculations of the Gaoqiao tidal station, the sensitivities of maximum storm surge to typhoon center longitude, latitude, central pressure and the maximum wind radius were studied. The results show that the maximum increase of water is not sensitive to the latitude of the typhoon center, is a little sensitive to typhoon central pressure and maximum wind radius, and is the most sensitive to typhoon center longitude. The time of maximum increase of water is not sensitive to the typhoon central pressure and the maximum wind radius, but is more sensitive to typhoon center longitude and latitude, especially the latitude. Between the two types of simulated typhoon, the time of maximum increase of water is more sensitive to typhoon center latitude and moving speed. Related Articles | Metrics

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Ecological characteristics analysis of phytoplankton’s dominant species in summer and autumn in the Dianshan Lake, China YU Qiu-Jia, WANG Hao-Bin, TAN Yu-Feng, YOU Wen-Hui 2014, 2014 (6):  90-100.  doi: 10.3969/j.issn.10005641.2014.06.013 Abstract ( 1695 )   PDF (2110KB) ( 2081 )   Save In order to understand the ecological characteristics of phytoplankton’s dominant species and their relationships with environmental factors in summer and autumn in Dianshan Lake, a survey was conducted at 13 sampling sites from June to November 2012. The density and dominance and niche breadth were calculated in this study. The phytoplankton dominant species in the Dianshan Lake was composed of 17 species belonging to4 phylum and 12 genera. The density of phytoplankton’s dominant species which appeared every month and the total densityof phytoplankton were analyzed with pearson correlation,and we screened out that  Chlorella vulgaris, Chroomonas acuta, Melosira ambigua and  Cryptomonas rostrata were the main dominant species.The result of grey relationship analysis suggested that different phytoplankton density varied with the change of environmental factors, and the factors which seriously influenced each species were different in summer and autumn. In summer, transparency was the key factor that influenced the density of  Chlorella vulgaris, Melosira ambigua  and Cryptomonas rostrata. Dissolve oxygen wasthe key factor that influenced the density of  Chroomonas acuta.  In autumn, total phosphorus was the key factor that influenced the density of Chlorella vulgaris. Dissolve oxygenwas the key factor that influenced the density of Chroomonas acuta  and Cryptomonas rostrata. Total nitrogen was the key factor that influenced the density of  Melosira ambigua. Related Articles | Metrics

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Changes of the expression of tubulin genes during encystment and excystment of Euplotes encysticus WANG Xiao-Hui, WU Na, FAN Xin-Peng, GU Fu-Kang 2014, 2014 (6):  101-108.  doi: 10.3969/j.issn.1000-5641.2014.06.014 Abstract ( 1207 )   PDF (1737KB) ( 1805 )   Save The processes of encystment and excystment of the hypotrichous ciliate (Euplotes encysticus), were investigated using interference contrast microscopy and real-time quantitative PCR (Q-PCR). Results showed that the microtubular organelles were always in non-assembly and~assembly functional states; furthermore, the activity of the contractile vacuole during excystment played an important role in reassembly of cortical microtubular organelles and cellular activities, and meanwhile, the expression level of α-、β-和γ-tubulin genes changed relatively. During the dedifferentiation of the cortical microtubular organelles, cells formed the non-kinetosome-resorbing cysts and the expression of α-、β-和γ-tubulin genes showed a downward trend. During the re-differentiation of the cortical microtubular organelles, oral and somatic ciliature formed in order and cells rotated inside the cyst and soon after excysted to vegetative cells, while the gene expression of α-、β-和γ-tubulin showed an increasing tendency. During the whole process, the gene expression quantity from more to less wereβ-、α-和γ-tubulin, and the initial copies of the former two were much more than the latter's. It was revealed that during the processes of encystment and excystment of (Euplotes encysticus) with the differentiation of the cortical microtubule organelles, α-、β-和γ-tubulin gene were always in the different functional states relatively intracellular, as well as the γ-tubulin gene which works as microtubule organizing center. Related Articles | Metrics

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Crosslinking of decellularized heart valve by procyanidins in the acidic buffer solution: Compliance, anti-calcification and biological compatibility WANG Xiao-Ya, MA Xu-Bing, DI Wan-Yin, ZHANG Jia-Min, ZHU Zi-Yan, ZHANG Hong-Feng, CHANG Jiang 2014, 2014 (6):  109-120.  doi: 10.3969/j.issn.1000-5641.2014.06.015 Abstract ( 1335 )   PDF (4221KB) ( 1761 )   Save The aim of this study was to explore whether procyanidins (PC)-crosslinked acellular heart valves in acidic buffer solution can obtain the identical matrix compliance similar to non-crosslinked acellular ones with anti-calcification and good biocompatibility properties. Based on the different pH acidic buffer solutions of 1 mg/mL PC, the crosslinked acellular valves were crosslinked. The compliance was determined by bending angle measurement, anti-calcification by soaking in simulated body fluid, resistance to enzymatic degradation by collagenase-Ⅱ hydrolysis. Under pH 6.0 condition, PC crosslinked valve (PC1-pH 6.0) group was as soft as its non-crosslinked counterpart. Compared with non-crosslinked group (4.64 MPa), the ultimate tensile strength of PC1-pH 6.0 group reached up to 5.95 MPa while the elastic modulus maintained the same, showing higher tensile strength than and the same compliance as the decellularized valves. Calcification was completely inhibited after crosslinking at pH 6.0. Under this condition, the PC-crosslinked acellular valves can effectively resistant to proteolysis compatible to glutaraldehyde-crosslinked ones. Furthermore, acellular valves in PC1-pH 6.0 group provided a good substance for adhesion of heart valve interstitial cells and present anti-thrombosis potential. PC-crosslinked acellular valves in the Acidic Buffer Solution (pH 6.0) possess identical matrix compliance with non-crosslinked decellularized valves, potential of anti-calcification, resistance to enzymatic degradation, anti-thrombosis and good cytocompatibility, which may be used for preparing bioprosthetic heart valves. Related Articles | Metrics

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Cryopreservation of spores of Haplocladium microphyllum (Hedw.) Broth LI Qiu-Ping, JIANG Li-Jia, LU Bei-Bei, LIU Chang, XIAO Tian-Zhong, WU Si-Ping, WANG Jian, ZHU Rui-Liang 2014, 2014 (6):  121-125.  doi: 10.3969/j.issn.1000-5641.2014.06.016 Abstract ( 1114 )   PDF (382KB) ( 1704 )   Save Drying time and pretreatment temperature were explored to find out the optimum conditions of spores of  Haplocladium microphyllum storaged in Liquid nitrogen. Different time (1 d, 15 d, 30 d, 90 d, 180 d) of cryopreservation were studied using the optimum storage conditions and without any treatment. The spore average germination rate and protonema growth were compared before and after cryopreservation. The results showed that (1) After drying 5 h, --20oC low temperature pretreatment and thawing at room temperature conditions, the spore average germination rate was highest (88.26%), there were no significant difference between the average germination of spores of drying 5 h, 15--18oCand 20 h, --20oC low temperature pretreatment; (2) The average germination rate (88.26%) of spores stored in liquid nitrogen for 1 d was comparatively higher than that of the control (77.90%), the average germination rate of spores stored in liquid nitrogen for 30 d dropped to 6.03%, the spore average germination rate stored for 90 d appeared to rise and reaching 88.47%, the spore average germination rate stored for 180 d remained at 49.46% and the relative retention rate reached 63.49%. The results demonstrated the feasibility of cryopreservation for the long-term storage of spores of  Haplocladium microphyllum. Related Articles | Metrics

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Ontology construction and mathematical modeling for the LAS engines XING Wan-Li, WU Yong-He, MA Xiao-Ling 2014, 2014 (6):  126-140.  doi: 10.3969/j.issn.1000-5641.2014.06.017 Abstract ( 1224 )   PDF (431KB) ( 2100 )   Save Learning analytics system (LAS) has the potential to pull together diverse resources and services to leverage the best practices for education. As the central component of this system, current LAS engines have been limited in function and vaguely defined as well as poor scalability and extensibility to other contexts and institutions. This paper first proposed engine ontology, role, source, time and control, to describe and distinct four engine functions: Prediction, Reflection, Recommendation, and Adaptation, in order to establish a common language and practice for LA engines, and in turn improve interoperability between different LA applications. Based on those ontological engines, this study further designed a mechanism of LAS engines and applied mathematical modeling to explain its decomposition and recombination techniques. This LAS engines is expected to power an open and integrated LAS that is capable of scaling up and extensible to any context. Related Articles | Metrics